Abstract: A float assembly for a sensor provides a float member having a channel passing therethrough, a mounting for the sensor on the float, a guide passing through the channel for guiding the movement of the float member, a stop including a magnet located on the guide for limiting the movement of the float, and a magnetically activated switch included in the float member for activating when in proximity to the stop magnet for indicating that the float member is in proximity to the stop.

Abstract: A hydrocarbon sensor float for use in detecting the presence of hydrocarbons on the surface of a liquid provides an elongated floatation member having a top end and a bottom end and also having a cavity located centrally therealong and extending completely therethrough, a sensor assembly including a sensor and at least one electrical conductor coupled to the sensor, the sensor assembly being positioned in said floatation member for locating the sensor in the cavity for allowing access of the liquid thereto and for causing the electrical conductor to extend from the top end of the floatation member, and an attachment for a variable amount of weight at the bottom end of the floatation member for providing a variable floatation level for the member with respect to the liquid surface and likewise for the sensor for allowing adjustment of the detection depth for hydrocarbons at an installation site.

Abstract: A hydrocarbon responsive switch provides an elongated flexible member which is impervious to hydrocarbon substances, a hydrocarbon absorber bonded to the elongated flexible member for absorbing hydrocarbon substances in contact therewith and for swelling from the absorbing for causing the flexible member to bend, a mounting for one end of the elongated member, a first electrical contact located at the other end of the elongated member, and a second electrical contact for contacting the first contact upon bending of the elongated flexible member and thereby making electrical connection in response to the absorption of hydrocarbon substances by the absorber.

Abstract: A sensing device for detecting a substance including hydrocarbons on the surface of water provides a floatation device for floating on the water surface and for supporting at least one sensing element for detecting said substance, the floatation device being composed substantially of nitrile. A sensing device for use in an apparatus for detecting a substance on the surface of a liquid, the sensing device providing a mounting surface adapted for facing downwardly toward the liquid surface, a plurality of sensing elements each of which is mounted at a different predetermined distance below the mounting surface, and a flotation portion affixed to the mounting surface for supporting the mounting surface at the liquid surface whereby the sensing elements may be maintained at different known depths below the liquid surface.

Abstract: A sensing device for detecting a substance including hydrocarbons on the surface of water provides a floatation device for floating on the water surface and for supporting at least one sensing element for detecting the hydrocarbon substance with the floatation device is composed substantially of nitrile and having printed circuitry deposited on the nitrile for providing electrical connection between the sensing element and an electrical conductor for coupling the element to a sensing instrument.

Abstract: A device for sensing a substance on the surface of a liquid of the type including a float and a sensing element mounted on the float for extending into the liquid, includes a plastic encasement enclosing all portions of the element to be exposed to the liquid for preventing interference with the operation of the element by substances in the liquid other than the substance to be sensed.